TY - JOUR
T1 - Spin and Charge Interconversion in Dirac-Semimetal Thin Films
AU - Yanez, Wilson
AU - Ou, Yongxi
AU - Xiao, Run
AU - Koo, Jahyun
AU - Held, Jacob T.
AU - Ghosh, Supriya
AU - Rable, Jeffrey
AU - Pillsbury, Timothy
AU - Delgado, Enrique González
AU - Yang, Kezhou
AU - Chamorro, Juan
AU - Grutter, Alexander J.
AU - Quarterman, Patrick
AU - Richardella, Anthony
AU - Sengupta, Abhronil
AU - McQueen, Tyrel
AU - Borchers, Julie A.
AU - Mkhoyan, K. Andre
AU - Yan, Binghai
AU - Samarth, Nitin
N1 - Publisher Copyright:
© 2021 American Physical Society.
PY - 2021/11
Y1 - 2021/11
N2 - We use spin torque ferromagnetic resonance and ferromagnetic-resonance-driven spin pumping to detect spin-charge interconversion at room temperature in heterostructure devices that interface an archetypal Dirac semimetal, Cd3As2, with a metallic ferromagnet, Ni0.80Fe0.20 (permalloy). Angle-resolved photoemission directly reveals the Dirac-semimetal nature of the samples prior to device fabrication and high-resolution transmission electron microscopy is used to characterize the crystalline structure and the relevant heterointerfaces. We find that the spin-charge interconversion efficiency in Cd3As2/permalloy heterostructures is comparable to that in heavy metals and that it is enhanced by the presence of an interfacial oxide. Spin torque ferromagnetic resonance measurements reveal an in-plane spin polarization regardless of an oxidized or pristine interface. We discuss the underlying mechanisms for spin-charge interconversion by comparing our results with first principles calculations and conclude that extrinsic mechanisms dominate the observed phenomena. Our results indicate a need for caution in interpretations of spin-transport and spin-charge conversion experiments in Cd3As2 devices that seek to invoke the role of topological Dirac and Fermi arc states.
AB - We use spin torque ferromagnetic resonance and ferromagnetic-resonance-driven spin pumping to detect spin-charge interconversion at room temperature in heterostructure devices that interface an archetypal Dirac semimetal, Cd3As2, with a metallic ferromagnet, Ni0.80Fe0.20 (permalloy). Angle-resolved photoemission directly reveals the Dirac-semimetal nature of the samples prior to device fabrication and high-resolution transmission electron microscopy is used to characterize the crystalline structure and the relevant heterointerfaces. We find that the spin-charge interconversion efficiency in Cd3As2/permalloy heterostructures is comparable to that in heavy metals and that it is enhanced by the presence of an interfacial oxide. Spin torque ferromagnetic resonance measurements reveal an in-plane spin polarization regardless of an oxidized or pristine interface. We discuss the underlying mechanisms for spin-charge interconversion by comparing our results with first principles calculations and conclude that extrinsic mechanisms dominate the observed phenomena. Our results indicate a need for caution in interpretations of spin-transport and spin-charge conversion experiments in Cd3As2 devices that seek to invoke the role of topological Dirac and Fermi arc states.
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U2 - 10.1103/PhysRevApplied.16.054031
DO - 10.1103/PhysRevApplied.16.054031
M3 - Article
AN - SCOPUS:85119966303
SN - 2331-7019
VL - 16
JO - Physical Review Applied
JF - Physical Review Applied
IS - 5
M1 - 054031
ER -